The present invention relates to an apparatus having a pair of opposing surfaces driven by an actuator and, more specifically, by a piezoelectric device for clamping and/or valving purposes.
Clamps and valves are required in a wide variety of modern applications. For example, clamps and valves are used throughout industry, transportation, architecture, etc. As a result, many different types of clamps and valves have been designed for one or more specific applications.
Presently, electro-magnetic solenoids are used in a wide variety of clamping and valving applications. However, electro-magnetic solenoids have many shortcomings. In general, solenoids are relatively large and heavy. Solenoids consume relatively high amounts of power to remain energized. When supplied with only a reduced amount of power, solenoids operate unpredictably. It is difficult to maintain a solenoid in a partially open or partially closed position. Solenoids have relatively slow cycle times, provide weak opening and closing forces, and generate EMF (electromotive force). Differential pressure is required to operate most solenoids. When designed as a valve, most solenoids are gravity sensitive and include a fixed inlet valve port and a fixed outlet valve port requiring a predetermined installation orientation. Recently, piezoelectric bimorphs have also been used in some valve applications. Piezoelectric bimorph valves have several advantages including low power consumption, small size, light weight, and fast cycle times. Piezoelectric bimorph valves can be operated in a partially open or partially closed valve position. However, such valves produce relatively weak valve sealing forces resulting in substantial potential for fluid leakage.
The present invention provides an apparatus having at least one pair of opposing surfaces formed on a support structure for movement relative to one another and an actuator operably engaging the support structure for driving the at least one pair of opposing surfaces relative to one another in response to an electrical activation of the actuator. Preferably, the actuator is a piezoelectric device. The apparatus can be adapted for clamping and/or valving applications.
Other objects, advantages and applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.